Speeds increased significantly during Friday's two NASCAR Sprint Cup Series test sessions at Daytona International Speedway. Martin Truex Jr. topped 204 miles per hour in the morning session and Kurt Busch topped 206 mph in the afternoon. In both cases, though, they were running in tight drafts, a formation that always produces speeds faster than the single-car runs on Thursday.

On Thursday night, after testing concluded and drivers were polled, officials made more rules changes. They expanded the restrictor plate openings by 1/32nd-inch to 15/16th-inch, which produced upwards of 25 more horsepower. They also lowered the radiator pressure relief valve from 30 psi to 25 psi and narrowed the cars' grille openings. Officials hoped the changes would help increase engine temperatures and thus discourage two-car, tandem-style, “love-bug” drafting.

On Friday, the changes didn't seem to work all that well. At NASCAR's request, drivers ditched the two-car drafts and instead ran in the long-familiar “pack drafts.” Officials wanted drivers to stay together as long as possible to download data that may be used to issue more aerodynamic changes. In some cases Friday afternoon, the draft pack included at least a dozen cars.

Truex Jr., in a Toyota, was drafting with Michael Waltrip Racing teammate Clint Bowyer when both ran 204.722 mph. Behind them in the morning session were Richard Petty Motorsports drivers Marcos Ambrose and Aric Almirola, both at 203.142 mph in Fords. Mark Martin, another Toyota driver for MWR, was fifth-fastest at 201.748 mph. Jamie McMurray and teammate Juan Pablo Montoya (Chevys for Earnhardt-Ganassi-Sabates Racing), Jeff Gordon (Chevy for Hendrick Motorsports), Kurt Busch (Chevy for Phoenix Racing) and A.J. Allmendinger (Dodge for Penske Racing) completed the top-10 in the morning.

“Two-oh-five (mph) is pretty fast and the car is just now starting to get where it's almost on edge,” Truex Jr. said before the afternoon session. “We're almost pushing the limits of the grip, so it's going to get interesting with a lot of cars out there (in the second session). You can't really make fast maneuvers like you could before switching lanes. You really have to be smooth pushing, so it's definitely going to be exciting for sure.”

After the morning session, Sprint Cup Series director John Darby said he and his staff aren't ready to say that 204 mph and 205 mph are too fast. “We've been at 202, 203 during the races (at Daytona Beach and Talladega) for the last four plate races,” he said. “When you look at it that way, (it's just) a mile an hour quicker. At the same time, we constantly look to test and upgrade liftoff speeds. There's a new fin down the back window that's there to increase that liftoff speed. Two-oh-four is exciting (but) I don't think it's nervous yet. So we're okay.”

NASCAR president Mike Helton explained that this week's test is primarily to get aerodynamic baselines before teams return for the Feb. 26 Daytona 500. “We watch the speeds and everybody knows we watch the speeds,” he said. “There's a balance between what we're comfortable with (and not). The good thing is because of the technology and things we have access to, and the effort by the guys at the R&D Center, we've learned a lot (about) being able to contribute to that liftoff speed.

“But it's one of those things we have to monitor. It's a test, so we may be a little bit more lenient than we would be on race weekend. But we'll see how everything settles out and what kind of rule package we come back with. Like John said, 204 is okay for a test; it's okay for now. But we'll have to take back everything we learn and make a decision after that.”